I have sand in my planted tank, some sort of silica blasting sand. The problem is that it's ultra fine and insanely white. This makes maintenance very difficult. I'd like to use pfs instead, but I don't want to disturb the plants and their root systems. I'm having to replish frequently, since the sand gets sucked up so easily when vacuuming, it seems if i come within 6 inches of it. Would it be a problem to layer pfs over top of it? Since it is so fine, would the layer underneath cause any problems?